ICND1 – TCP & UDP Questions

Three types of flow control are buffering, windowing & congestion avoidance:

+ Buffering: If a device receives packets too quickly for it to handle then it can store them in a memory section called a buffer and proceed them later.

+ Windowing: a window is the quantity of data segments that the transmitting device is allowed to send without receiving an acknowledgment for them. For example:

With the window size of 1, the sending device sends 1 segment and the receiving device must reply with 1 ACK before the sending device can send the next segment. This “waiting” takes some time.

By increasing the window size to 3, the sending device will send up to 3 segments before waiting an ACK -> helps reduce the waiting time.

+ Congestion avoidance: lower-priority traffic can be discarded when the network is overloaded -> minimize delays.

Question 2

Question 3

Explanation

HTTP is based on TCP connection so a TCP connection must be established first between the workstation and the web server.

Question 4

Explanation

Before two computers can communicate over TCP, they must synchronize their initial sequence numbers (ISN) -> B is correct.

TCP uses a sequence number to identify each byte of data. The sequence number identifies the order of the bytes sent from each computer so that the data can be reconstructed in order, regardless of any fragmentation, disordering, or packet loss that may occur during transmission -> D is correct.

to jde
you can try the following steps in you computer
1> from cmd line, you can ping 127.0.0.1 which is your loopback address
2> go to network connections,
3> click the LAN and un-select the TCP/IPv6 and TCP/IPv4
4> no you are not able to ping 127.0.0.1 from cmd line.